The first time it happened was a hot August day in Maryland, the kind where the nicotine-saturated air inside the tiny, heavily air-conditioned house seemed to vie with the humidity and traffic haze outside, each competing to be more noxious than the other. Late in the afternoon, as I left for my night shift summer job, the steamy transition zone at the front door hit me with a silent thud. Sweat was already starting to bead on my back as I rolled down the windows in my Datsun. I drove around the corner, then turned onto the three-lane highway.

As long as I didn't hit too many red lights, there was enough wind through the windows to keep the commute tolerable. My canvas Topsiders sat on the passenger side floor as my bare feet danced between accelerator, clutch, and brake. I was heading to Annapolis, where I would spend much of the night in the basement of a government office building, typing information from traffic tickets into the state's computer system. It was mind-numbingly boring, but for a college student living in his parents' house who just needed book and beer money for the coming academic year, the pay was more than adequate.

At the intesection with the main four-lane highway, I just missed the light and knew I would be waiting there for a few minutes. Sliding the stick into neutral and releasing the clutch, I looked down the recently built "rail trail" that extended into the woods from the intersection.

I was just a few weeks away from starting my junior year as a biology major, and my lifelong wonder at the natural world was becoming steadily more focused and informed. Taking apart the scene along the bike trail, I saw a riot of plant life condensing the late afternoon sunlight into food for the coming winter, heard a chorus of cicadas, crickets and frogs seeking their mates, and smelled - even above the exhaust fumes and hot asphalt - a whiff of earthy decay emanating from the legions of worms, fungi, and bacteria as they turned yesterday's life into tomorrow's soil.

Putting the elements together, I was suddenly struck by the relentlessness of it all. Even here, in the midst of sprawling strip malls and highways, life didn't just survive, it strove. Each organism was working to advance its own interests, around the clock, throughout the year, everywhere. It never stopped. It would never stop. Ever. If we go extinct - and the odds certainly favor it - all of this will still go on, little noting nor long remembering the momentous historical events we thought were so important.

A familiar feeling of awe came over me. It was exactly like standing under a dark, clear sky and seeing the Milky Way in all its splendor. There's all that space, all those planets and stars and galaxies, and here we are, tiny creatures on a tiny world adrift in the midst of it.

But as I realized on that August afternoon, we don't have to look up to feel insignificant in the face of the infinite. Biology just hides its inifinities better than astronomy. Instead of extending across the sky in brilliant points of light, the wonders of life extend across time and scale, into dimensions we can only glimpse fleetingly. When we do, though, they're no less amazing than the expanse above us.

In the first edition of his seminal Origin of Species, Darwin famously concluded:

There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

The sentence, which in later editions added a reference to "the Creator," was widely seen as an attempt to placate devout Christians after comprehensively disproving a literal interpretation of their faith's creation myth. On that score, Darwin's "grandeur" must have seemed cold comfort, replacing generations of transformative mystical revelations with a dry, rational framework. Maybe you changed your life because you thought you'd found God, Darwin seemed to say, but you didn't, you just saw a byproduct of this abstract mechanism I've been geeking about for the past several hundred pages. Isn't that neat?

After glimpsing the infinite on that summer afternoon at the crossroads, I take a grander view. Given all that Darwin had experienced, I think he was trying to express his sincere joy at what seemed to him an entirely new kind of mystical experience. Instead of God, he'd seen Life, which is far more beautiful and powerful. This, too, can change lives.

A few years later, my pursuit of that grandeur took me to graduate school. One night, working alone in a laboratory with a million-dollar view of New York City, I was streaking bacteria onto agar plates. The bacteria - at least some of them, I hoped - carried pieces of human DNA that I'd inserted into them. It felt like a mundane chore, because it was. The human DNA and the bacteria were merely tools to accomplish the overall project I was working on, trying to understand how poliovirus gets into cells.

I looked out the window at the city lights for a moment, then back to the plates, and that wave of wonder I'd felt at the traffic light came rushing back with renewed force. Life, in all its relentless splendor, was sitting in my hands and I was manipulating it for my own purposes, using procedures that were now so well known they felt boring. With casual ease, I could reach right into those microscopic infinities, move molecules around, and use the altered life to reveal even more worlds. Take that, astronomy.

At first I thought that this God-like rush must be a modern experience, a product of the molecular biology revolution. Later, though, I realized that it followed a far more ancient tradition.

Look back before writing, to the first human tribes hunting and gathering their way across the land: the world's most powerfully motivated biologists. Being a good scientist meant your family got to eat. With no claws, inadequate teeth and mediocre running speed, we survived entirely by our brains. We formed theories, performed experiments, and published our results in oral traditions. Science and teamwork let us hunt game far larger than ourselves, and find abundant vegetables among the toxic weeds. Our power grew geometrically with our understanding of biology, and from the beginning we used that power to gain even more understanding.

A hunter studied his quarry's behavior, then built a trap to catch it alive so the meat wouldn't spoil. Watching it in captivity, he realized he could breed it with another to get even more meat later. If he picked which offspring to breed next, he could tame them and even change their size and shape. A gatherer timed her harvests to the seasons, then understood that she could plant the seeds closer to home to make the next crop easier to collect. Later, she picked only the plants that grew best for the next year's seed, and the wild, unpredictable harvest was replaced with a steady abundance for her and her heirs. How did it feel to wield such power over nature? I think I know.

Of course scientists don't spend all day agape over the beauty that surrounds them, any more than airline pilots scream in amazement throughout a Newark-to-Beijing flight, but the occasional moments of insight are enough to shape the trajectory of a career. When I left laboratory research to become a science writer, the most painful part was the thought that I was giving up those glorious epiphanies. I was mistaken.

A few years after leaving the lab, I was on a hiking trip in Utah. Growing up in the eastern US, I'd never experienced the stark, rugged terrain of the high desert before. Everything looked so naked, a towering landscape of nearly pure geology with only scraps of plant life and the odd rodent or reptile peeking from the cracks.

My wife and I didn't have a child yet, so we'd scheduled our trip for late September to avoid the summer vacation crowds. We had the trails to ourselves. The two of us walked in near silence up a steep series of switchbacks hewn into the canyon walls by the Civilian Conservation Corps. The midday sun blazed in a cobalt sky that stretched down to the browns and reds of sandstone cliffs. Far below, a river was visible only by the mass of cottonwood trees that crowded its banks, alongside the sole road into the dead-end canyon. It was easy to see why the first white settlers here had called the place Zion: the promised land, the holy fortress.

Pausing for a moment, I looked at the rock that extended straight up beside my shoulder. The closer I looked, the more layers I could see in the sandstone, splitting the eons of its accumulation in ancient seas, lakes, and rivers. I realized I could place my hand over a span of rock that had probably taken longer than recorded human history to form. Then I turned around.

My view across the canyon encompassed thousands of vertical feet of rock faces. Hundreds of millions of years. Algae, bacteria, primitive fishes. Rivers flowing, meandering, vanishing. Lakes forming, draining, forming again, drying up. Seas whose tides flowed daily through ten thousand lifetimes, then stopped. Then there was a slow rise, the former sea floor lifting up above the shoreline, until the shoreline was beyond the horizon and nothing but a trickling stream remembered it, twisting across the high plateau to erode a channel, then a ravine, then a valley, then a canyon so vast that a bizarre species of hyper-intelligent apes would trek here by the millions just to see it.

Deep. Time.

A dark sky shows us how small we are; a deep canyon shows us how brief. And yet it also shows us our eternal heritage, billions of years of relentless struggle to reach this one moment, this epiphany of endurance in the face of unimaginable frailty. Life goes on. And on, and on, and on.

Science grants us the privilege of seeing the universe as it really is: unfathomably beautiful and unspeakably terrifying. We are tiny, fragile, and isolated in the vastness of space. We are also powerful, enduring, and tireless, the survivors of millions of generations of brutal competition, finally able to see ourselves and our world in all its glory. What's more, this view of life is democratic. Like a national park, it's everyone's birthright.

For as long as we've been a species, we've observed, hypothesized, and tested. The ancient Greeks codified the scientific method, and modern society has specialized and professionalized it, but it's really a fundamental part of humanity that has made us what we are. Science has given us the kingdom, and the power, and the glory. Monotheistic religions tried to claim dominion over it, but the animists who preceded them had it right: truth is in nature, accessible to all. There is a grandeur in this view of life. Go see for yourself.